ON EXCEPTIONS TO REPORT OF SPECIAL MASTER.
Blackmun, J., delivered the opinion for a unanimous Court.
JUSTICE BLACKMUN delivered the opinion of the Court.
These supplemental proceedings in this wide-ranging litigation are to determine the legal coastline of the United States in the area of Block Island Sound and the eastern portion of Long Island Sound. That determination turns on whether Long Island Sound and Block Island Sound constitute, in whole or in part, a juridical bay under the provisions of the Convention on the Territorial Sea and the Contiguous Zone (the Convention).*fn1 To the extent the Sounds constitute a juridical bay, the waters of that bay, under the Convention,
are then internal waters subject to the jurisdiction of the adjacent States, and the line that closes the bay is coastline for the purpose of fixing the seaward boundaries of the States.
The Special Master concluded (a) that the Sounds in part do constitute a juridical bay, and (b) that the bay closes at the line drawn from Montauk Point, at the eastern tip of Long Island, to Watch Hill Point on the Rhode Island shore. We have independently reviewed the voluminous record, as we must, see Mississippi v. Arkansas, 415 U.S. 289, 291-292, 294 (1974); Colorado v. New Mexico, 467 U.S. 310, 317 (1984), and find ourselves in agreement with the Special Master. We therefore adopt the Master's findings, confirm his conclusions, and overrule the respective exceptions filed by the United States, the State of New York, and the State of Rhode Island and Providence Plantations.
This action, invoking the Court's original jurisdiction under U.S. Const., Art. III, § 2, and 28 U. S. C. § 1251(b)(2), was instituted in 1969, see 395 U.S. 955, with the filing of a complaint by the United States against the 13 States that border the Atlantic Ocean.*fn2 The purpose of the suit was to determine whether the United States had exclusive rights to the seabed and subsoil underlying the ocean beyond three geographical miles from each State's coastline. See Submerged Lands Act of 1953, 67 Stat. 29, 43 U. S. C. § 1301 et seq. In due course, after the filing of answers, the appointment of a Special Master, 398 U.S. 947 (1970), the submission of the Master's Report, the filing of exceptions thereto, and oral argument,*fn3 this Court delivered its opinion,
U.S. 515 (1975), and entered a general decree, 423 U.S. 1 (1975). The Court there determined that the States held interests in the seabeds only to a distance of three geographical miles from their respective coastlines. The Court did not then fix the precise coastline of any of the defendant States; instead, jurisdiction was reserved "to entertain such further proceedings, including proceedings to determine the coastline of any defendant State, to enter such orders, and to issue such writs as may from time to time be deemed necessary or advisable to give proper force and effect to this decree." Id., at 2.*fn4
Meanwhile, in an unrelated federal action, pilots licensed by Connecticut challenged a Rhode Island statute which requires every foreign vessel and every American vessel under register for foreign trade that traverses Block Island Sound to take on a pilot licensed by the Rhode Island Pilotage Commission. The District Court in that suit ruled that Rhode Island possessed the authority so to regulate pilotage in the Sound. Its theory was that the State had that authority under 46 U. S. C. § 211, a statute which gives the States power to regulate pilots in "bays, inlets, rivers, harbors, and ports of the United States." In so ruling, the court determined that Block Island Sound was a bay under the Convention and therefore qualified as internal waters within Rhode Island's coastline. Warner v. Replinger, 397 F.Supp. 350, 355-356 (RI 1975). The United States Court of Appeals for the First Circuit affirmed that judgment. Warner v. Dunlap, 532 F.2d 767 (1976), cert. pending sub nom. Ball v. Dunlap, No. 75-6990.
In December 1976, obviously in response to the ruling in the Rhode Island Pilotage Commission suit, and apparently
in the thought that coastline determinations would best be made in this then-existing original action, the United States filed a motion for supplemental proceedings to determine the exact legal coastlines of Massachusetts and Rhode Island. This Court entered an order appointing the Honorable Walter E. Hoffman as Special Master, with the customary authority to request further pleadings, to summon witnesses, to take evidence, and to submit such reports as he might deem appropriate. 433 U.S. 917 (1977). The Massachusetts component of the litigation was separated from the Rhode Island component when it became clear that each concerned different issues. See n. 4, supra. Subsequently, the Master granted New York's motion to participate in the Rhode Island proceedings.
The basic position of the United States is set forth in the following allegations of its second amended complaint:
"The coastline of Rhode Island is the line of ordinary low water along that portion of the coast which is in direct contact with the open sea and the line marking the seaward limit of inland waters.
". . . [The] coast of the the State of Rhode Island, except as to Block Island, is the ordinary low water line along the mainland beginning at the Massachusetts border to a point off Sakonnet Point, then a straight closing line across Narragansett Bay to Point Judith, then the ordinary low water line along the mainland to the Connecticut border. As to Block Island, the coast of the State of Rhode Island is the ordinary low water line around Block Island. . . ."
Rhode Island's basic position is asserted in its counterclaim:
"[The] Rhode Island coast is the ordinary low water line along the mainland beginning at the Massachusetts border to a point off Sakonnet Point, then a straight closing
line from Sakonnet Point west to Point Judith, then a straight closing line south to Sandy Point on Block Island, then the ordinary low water line along the Block Island shore clockwise, to a point along a straight closing line to Montauk Point on Long Island, State of New York."
The status of Long Island Sound as internal waters over which the States have jurisdiction is no longer at issue, for the parties agree, as the Master had found, that Long Island Sound is a historic bay under Article 7(6) of the Convention. We, too, agree with that determination. Its waters therefore are internal waters regardless of whether it also is in part a juridical bay.*fn5
In his Report, the Special Master concluded that Long Island Sound and Block Island Sound constitute a juridical bay under the Convention, especially as interpreted by this Court's decision in United States v. Louisiana (Louisiana Boundary Case), 394 U.S. 11 (1969). The Master so found after concluding that Long Island is to be viewed as an extension of the mainland and as constituting the southern headland of the bay. The Master went on to conclude, as noted above, that the bay closes at the line drawn from Montauk Point, at the eastern tip of Long Island, to Watch Hill Point on the Rhode Island shore.
The Special Master's Report, when received here, was ordered filed, and exceptions thereto, and replies, were authorized. 465 U.S. 1018 (1984). In response, the United States, the State of Rhode Island, and the State of New York each filed exceptions. These were set for oral argument. 468 U.S. 1213 (1984). The case is now before us on the
Report, the exceptions, and the briefs and arguments of the parties.
In this Court, the United States argues that it "[quarrels] only with the Special Master's recommendation that Long Island be deemed a part of the mainland and the consequences that necessarily flow from that ruling." Exception of United States 5. It states that if Long Island is considered an island, rather than an extension of the mainland, it cannot form a juridical bay. It expresses concern about "the principle involved and the precedent created," id., at 6, if its not-part-of-the-mainland argument is rejected, because of the effect of that decision on other States and its international implications. The United States argues that current social and economic ties between Long Island and the mainland cannot overcome the geographical separateness of the Island. It states that any emphasis on the "bay-like" appearance and usage of the waters sheltered by Long Island is "reasoning backwards." Id., at 8. The Court should affirm, or really reaffirm, that a "geographical island is an island in the eye of the law except only in very rare and truly unusual circumstances." Id., at 9. It finds support in Louisiana v. Mississippi, 202 U.S. 1 (1906), and in the Louisiana Boundary Case, supra, and it points out that Long Island Sound indeed has been referred to, even by this Court, as "an insular formation." See 394 U.S., at 72, n. 95.
Before this Court, Rhode Island has directed its exceptions to the fixing of a line that closes what it claims is a juridical bay consisting of Long Island Sound and Block Island Sound. Although it agrees with the other parties that Montauk Point is the bay's southern headland, Rhode Island argues that Watch Hill Point cannot be the northern headland, if for no other reason than that a point east of Watch Hill Point (near Quonochontaug Pond) is a preferred choice, for it, too, would satisfy all required conditions and would enclose more water area. But Rhode Island further notes that Block Island lies
at the opening of the long and deep indentation formed by the two Sounds. It is said that although Block Island lies seaward of a direct line from Montauk Point to Point Judith, it nevertheless influences Block Island Sound in a number of significant ways: coastal traffic routinely passes outside Block Island; commercial vessels rarely go between Montauk Point and Block Island because of the hazardous underwater conditions there; Block Island provides shelter in rough weather; the salinity of the water in Block Island Sound is less than that of water of the open sea; the ...